1. Phenotypic Re-expression of Near Quiescent Chondrocytes: The Effects of Type II Collagen and Growth Factors
- Author
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Tsung Tan Tsai, Wen-FuThomas Lai, Shih Ching Chen, Chia Lang Fang, Li Hsuan Chiu, Chin Chean Wong, and Yu-Hui Tsai
- Subjects
Materials science ,Base Sequence ,Biomedical Engineering ,Type II collagen ,Cell Differentiation ,Matrix (biology) ,Polymerase Chain Reaction ,Chondrocyte ,Cell biology ,Biomaterials ,Glycosaminoglycan ,Extracellular matrix ,Collagen, type I, alpha 1 ,Chondrocytes ,Phenotype ,medicine.anatomical_structure ,Biochemistry ,medicine ,Animals ,Rabbits ,Growth Substances ,Collagen Type II ,Type I collagen ,Aggrecan ,DNA Primers - Abstract
After extensively expanding in monolayer culture, the cultured chondrocytes become quiescent. The aim of this study was to establish the hypothesis that the phenotypic function of extensively expanded primary chondrocytes may be restored with extracellular matrix (ECM) compositions with or without growth factors. The restoring effects of these microenvironmental factors on the near quiescent passage 9 (P9) chondrocyte were investigated. The data showed that exogenous type I collagen and type II collagen at 1:1 ratio stimulate cell proliferation greatly while type II collagen alone was enough to revive most of cartilaginous functions of near quiescent P9 chondrocytes. Exogenous type II collagen by itself was more effective in restoring cell proliferation rate, elevating glycosaminoglycan (GAG) accumulation and promoting the re-expression of type II collagen mRNAs in the near quiescent chondrocytes. The supplement of P9 chondrocytes with type II collagen plus TGF- β1 and IGF-I appeared essential for the re-expression of aggrecan and type II collagen mRNA in monolayer culture. In 3D type II collagen construct, P9 chondrocytes appeared healthy as chondrocytes and showed clear lacuna. However, in 3D type I collagen matrix, only some P9 chondrocytes exhibited lacuna. The cartilaginous microenvironments are crucial to restoring chondrocyte-phenotypic features of the quiescent or ‘dedifferentiated’ chondrocytes, implicating the potential of expanding a scarcity of healthy chondrocytes for cartilage repair or regeneration.
- Published
- 2009